The HTTP server account should be a standard account, preferably in a
group of its own (definitely at least a non-system, non-user group), with
sufficient quotas to handle the expected traffic.
5.1 - VMS Account
PROCESS QUOTAS: Server process quotas must be sufficient to support the expected traffic load. In particlular PRCLM must support expected script usage. BYTLM, BIOLM, DIOL, FILLM and PGFLQUO are all significant considerations. Symptoms of insufficient process quotas include:
Username: HTTP$SERVER Owner: HyperText Daemon
Account: HTTPD UIC: [377,377] ([HTTPD,HTTP$SERVER])
CLI: DCL Tables: DCLTABLES
Default: HT_ROOT:[HTTP$SERVER]
LGICMD: LOGIN
Flags: Restricted DisNewMail
Primary days: Mon Tue Wed Thu Fri
Secondary days: Sat Sun
Primary 000000000011111111112222 Secondary 000000000011111111112222
Day Hours 012345678901234567890123 Day Hours 012345678901234567890123
Network: ##### Full access ###### ##### Full access ######
Batch: ##### Full access ###### ##### Full access ######
Local: ----- No access ------ ----- No access ------
Dialup: ----- No access ------ ----- No access ------
Remote: ----- No access ------ ----- No access ------
Expiration: (none) Pwdminimum: 6 Login Fails: 0
Pwdlifetime: 90 00:00 Pwdchange: (pre-expired)
Last Login: (none) (interactive), 11-MAY-1995 08:44 (non-interactive)
Maxjobs: 0 Fillm: 300 Bytlm: 300000
Maxacctjobs: 0 Shrfillm: 0 Pbytlm: 0
Maxdetach: 0 BIOlm: 512 JTquota: 1024
Prclm: 100 DIOlm: 512 WSdef: 1000
Prio: 4 ASTlm: 600 WSquo: 2000
Queprio: 0 TQElm: 100 WSextent: 20000
CPU: (none) Enqlm: 256 Pgflquo: 200000
Authorized Privileges:
NETMBX TMPMBX
Default Privileges:
NETMBX TMPMBX
NOTE: Support procedures often change between versions. It is always advisable to check the versions documentation before installing or updating.
Examples may be found in
HT_ROOT:[EXAMPLE].
HTTPd Executables
Two server executables are built by the package.
Two additional executables are built by the SSL package (see 10 - Secure Sockets Layer).
As this image is to be installed with privileges unauthorized use should be prevented by applying an ACL similar to the following against the executable image:
$ SET SECURITY HT_EXE:HTTPD.EXE -
/ACL=((IDENT=HTTP$SERVER,ACCESS=R+E),(IDENT=*,ACCESS=NONE))
This can be done once, at installation, or for peace-of-mind (a.k.a. VMS-ish paranoia) at each server startup.
As the HTTP$SERVER account should be completely unprivileged, and the HTTPd image requires NETMBX, TMPMBX, PRMMBX, PSWAPM, SYSNAM and SYSPRV privileges (see the "Nuts and Bolts" document for a description of how and why the server uses these privileges). It must be installed using a command similar to the following:
$ INSTALL = "$SYS$SYSTEM:INSTALL/COMMAND_MODE" $ INSTALL ADD HT_EXE:HTTPD.EXE /PRIVILEGE=(ALTPRI,PRMMBX,PSWAPM,SYSPRV,SYSNAM)
The following logical names are essential for the operation of the HTTPd server and must be defined before startup:
The following logical name is created by the executing HTTP server and defines the name of the control mailbox:
The following logical names are created by the executing HTTP server if the HTTPd monitor utility is enabled:
The server process log directory (output for the detached HTTP server processes) may require explicit access controls for the HTTPd account. This can be done by applying an ACL similar to the following:
$ SET SECURITY HT_ROOT:[LOG]SERVER.DIR -
/ACL=((IDENT=HTTP$SERVER,ACCESS=R+W+E, OPTIONS=DEFAULT), -
(IDENT=HTTP$SERVER,ACCESS=R+W+E), -
(IDENT=*,ACCESS=NONE, OPTIONS=DEFAULT), -
(IDENT=*,ACCESS=NONE))
As with the ACL on the server executable this can be done once, at
installation (or, if right over the top, at each server startup). Appropriate
disk quotas may also need to be applied. Also see
5.3.2.6 - Logging.
STARTUP.COM
Putting all this together the HTTP server startup procedure becomes something similar to the supplied example. It should be called from SYSTARTUP_VMS.COM or the site's equivalent.
See
HT_ROOT:[EXAMPLE]STARTUP.COM
STARTUP_LOCAL.COM
This file is automatically executed by the STARTUP.COM procedure immediately before the server is actually started. It is provided to supply all the local site's additional startup requirements. Place site-specific server environment startup in here, leaving STARTUP.COM alone as much as possible.
See
HT_ROOT:[EXAMPLE]STARTUP_LOCAL.COM
HTTPD_BATCH.COM
This procedure is SUBMITted by the server STARTUP.COM using the HTTP server account, and simply creates a detached process under the control of HTTPD80.COM, or its equivalent. A parameter may be provided to this procedure. This roughly represents the port number of a server but actually represents a file HTTPD'number'.COM which controls a specific server, see below.
See
HT_ROOT:[EXAMPLE]HTTPD_BATCH.COM
HTTPD80.COM
This procedure is suggested for controlling the execution of the HTTPd server and it's image. It is run in the detached process created by HTTPD_BATCH.COM. Multiple instances of this file may be created, each having a unique number, for controlling multiple servers, either on an individual node or within a cluster. Actually, just any unique string may be used for indentification.
See
HT_ROOT:[EXAMPLE]HTTPD80.COM
LOGIN.COM
This procedure provides the HTTP server account login control.
See
HT_ROOT:[EXAMPLE]LOGIN.COM
5.3 - HTTPd Command Line
Command-line qualifiers provide some server startup control as well as
server runtime control.
5.3.1 - Server Startup
When starting up the server several characteristics of the server may be specified using qualifiers on the command line. If not specified appropriate defaults are employed.
Note: buffer sizes apply on a per-request (thread)
basis, and may be tailored for specific environments at server startup.
5.3.2 - Server Command Line Control
A foreign command for the HTTPD control functionality will need to be assigned in the adminstration users' LOGIN.COM, for example:
HTTPD == "$HT_EXE:HTTPD" !HTTPD == "$HT_EXE:HTTPD_NETLIB"
Some control of the executing server is available from the DCL command
line on the system on which it is executing. This functionality, via the
"/DO=" qualifier, is available to the privileged user. If a non-default
server port, or multiple servers on the one system are being used, then it
will be necessary to provide a "/PORT=" qualifier with any command, and
possibly issue it multiple times. Of course, these commands are available from
batch jobs as well as interactively.
5.3.2.1 - Accounting
Server counters may be zeroed. These counters are those visible from the statistics admininstration menu item and when using the HTTPDMON utility.
$ HTTPD /DO=ZERO
See 9 - Authentication and Authorization.
The authorization rule file (HTTP$AUTH) may be reloaded.
$ HTTPD /DO=AUTH=LOAD
The authentication cache may be purged, resulting in re-authentication for all subsequent authorization-controlled accesses. This may be useful when disabling authorization or if a user has been locked-out due to too many invalid password attempts.
$ HTTPD /DO=AUTH=PURGE
Server cache control may also be exercised from the server administration menu, see 11 - Server Administration. The file cache (see 13 - Cache) may be enabled, disabled and have it's contents purged (declared invalid and reloaded) using
$ HTTPD /DO=CACHE=ON $ HTTPD /DO=CACHE=OFF $ HTTPD /DO=CACHE=PURGE
These commands can be useful for flushing any currently executing CGIplus applications from the server, enabling a new version to be loaded with the next access. See 12 - Scripting.
All scripting subprocesses, busy with a request or not, can be deleted (this may cause the client to lose data).
$ HTTPD /DO=DCL=DELETE
A gentler alternative is to delete idle subprocesses and mark busy ones for deletion when completed processing.
$ HTTPD /DO=DCL=PURGE
All DECnet connections, busy with a request or not, can be disconnected (this may cause the client to lose data).
$ HTTPD /DO=DECNET=DISCONNECT
Purging is a better alternative, disconnecting idle tasks and marking busy ones for disconnection when complete.
$ HTTPD /DO=DECNET=PURGE
Server logging control may also be exercised from the server administration menu, see 11 - Server Administration.
Open a log file.
$ HTTPD /DO=LOG=OPEN
Optionally open and specify a log file name. This overrides any /LOG=file-name or HTTPD$LOG specified file name.
$ HTTPD /DO=LOG=OPEN=file-name
The log file may be closed and reopened using a different name (allowing continuous operation but, for example, with daily log files). This overrides any /LOG=file-name or HTTPD$LOG specified file name.
$ HTTPD /DO=LOG=REOPEN=file-name
Close the log file.
$ HTTPD /DO=LOG=CLOSE
Unwritten log records may be flushed to the file.
$ HTTPD /DO=LOG=FLUSH
The format and period specification of the log may be changed (only takes effect after the next log file open/reopen) using
$ HTTPD /DO=LOG=FORMAT=string $ HTTPD /DO=LOG=PERIOD=string
See 8 - Mapping Rules.
The mapping rule file (HTTP$MAP) may be reloaded.
$ HTTPD /DO=MAP
Server shutdown may also be exercised from the server administration menu, see 11 - Server Administration.
The server may be shut down, without loss of existing client requests. Connection acceptance is stopped and any existing requests continue to be processed until conclusion.
$ HTTPD /DO=EXIT
The server may be immediately and unconditionally shut down.
$ HTTPD /DO=EXIT=NOW
The server may be restarted, without loss of existing client requests. Connection acceptance is stopped and any existing requests continue to be processed until conclusion. This effectively causes the server to exit normally and the DCL wrapper procedure to restart it.
$ HTTPD /DO=RESTART
This variant restarts the server immediately regardless of existing connections.
$ HTTPD /DO=RESTART=NOW
A multi-homed host responds to connections for more than one network address. Details on configuring Digital TCP/IP (UCX) for this behaviour may be found in the Digital TCP/IP Management manual, section on "Subnetwork Routing" (3.4.8 in the November 1995 edition) and Digital TCP/IP Management Command Reference, section on "SET INTERFACE" (November 1995 edition). The server configuration parameter [Service] allows for the processing of requests for multiple host-names and/or ports (see 6.2 - Directives) while conditional mapping rules enhance this basic capability (see 8.5 - Conditional Mapping).
Assuming an alternate, unused host name exists (for example):
$ UCX
UCX> SET HOST "second.host.name" /ADDRESS=131.185.30.2 /ALIAS=("second","SECOND")
UCX> [EXIT]
$
The system IP interface can be determined as follows (in this example it is SE0, the LO0 is the localhost interface):
UCX> SHOW INTERFACE
Packets
Interface IP_Addr Network mask Receive Send MTU
SE0 131.185.30.1 255.255.0.0 595567 262764 1500
LO0 127.0.0.1 255.0.0.0 1 573 65535 ?
UCX> SHOW INTERFACE SE0 /FULL
Interface: SE0
IP_Addr: 131.185.30.1 NETWRK: 255.255.0.0 BRDCST: 131.185.255.255
Ethernet_Addr: AA-00-04-00-59-04 MTU: 1500
.
.
.
Restarting attempts 0
Successful restarts 0
Note the network and broadcast masks of the interface above. The basic procedure then is to create a pseudo-interface (the "A" added to the hardware device name) as follows:
UCX> SET INTERFACE SEA0 /HOST="second" /NET=255.255.0.0 /BROAD=131.185.255.255 UCX> SET PROTOCOL IP /FORWARD
After the above commands the interfaces should appear as shown below:
UCX> SHOW INTERFACE
Packets
Interface IP_Addr Network mask Receive Send MTU
SE0 131.185.30.1 255.255.0.0 595567 262764 1500
SEA0 131.185.30.2 255.255.0.0 169 99 1500
LO0 127.0.0.1 255.0.0.0 0 2263 65535 ?
These commands can be done interactively, during each startup, or placed in the permanent UCX configuration database once, as follows:
UCX> SET CONFIG INTERFACE SEA0 /HOST="second" /NET=255.255.0.0 /BROAD=131.185.255.255 UCX> SET CONFIG PROTOCOL IP /FORWARD
Digital TCP/IP Services v4.1 at least, appears to determine an outgoing connection's originating host address from the IP address of the "highest" pseudo-interface defined (in this case from the SEA0, resulting in an apparent source address of 131.185.30.2). This can cause some confusion on remote hosts as to the origin of a connection, and otherwise be generally undesirable.
A solution appears to be to assign the primary address to the last defined interface. This means the original interface must be removed using a
UCX> SET CONFIG NOINTERFACE SE0then explicitly redefining it and then the new interface, ensuring the first is the non-primary address and the second the primary.